1. Field of the Invention
The present invention relates to a mobile terminal, and more particularly, to a charging control apparatus and method of a mobile terminal, capable of charging the mobile terminal at different charging rates according to charging modes of an input voltage.
2. Description of the Related Art
Recently, MPEG layer-3 (MP3) players are actively developed which can replay music alone and also download music data to be replayed from a personal computer (PC) or Internet site through media, such as a transmission cable, and can be stored in a memory device.
Compared with the existing compact disk (CD) players, the MP3 players can be miniaturized and can delete and record data from and on the memory device at any time. Also, the MP3 players can enhance memory capacity and have a variety of functions such as broadcasting reception and viewing.
Meanwhile, the MP3 players are supplied with power from regular batteries (AA size, AAA size, etc.). Also, an internal battery installed inside the MP3 player is charged by a charging current applied through a power adaptor and is used as a power source.
Meanwhile, the recent MP3 players have universal serial bus (USB) ports that enable stored sound source data to be replayed, or enable sound source data to be received from other media. The USB port can be built in the body of the MP3 player, or connected to USB cable. To solve inconvenience to carry the USB cable and prevent missing the USB cable, MP3 players with a built-in USB cable are recently available in the markets. A charging current is also supplied through the USB and thus the internal battery built in the MP3 player is charged.
Meanwhile, a stereo speaker is provided in a body so as to listen to music vividly by replaying bass and clear original sound when reproducing digitalized sound source data. MP3 players with the USB port as well as the stereo speaker built in the body draw consumer's attraction.
FIG. 1 is a block diagram of a charging control apparatus of a related art portable audio player.
Referring to FIG. 1, a USB port 102 is connected to a communication port of a computer and is supplied with a charging current. The USB port 102 is also used to download sound source data. An external input port 104 is supplied with a charging current through the medium of AC/DC adaptor 101 for converting household AC power into DC voltage of a predetermined level necessary for charging. A selector 110 sets a supply path of a charging voltage by selecting one of the USB port 102 and the external input port 104. Also, when a charging current is supplied through one of the USB port 102 and the external input port 104 in a state in which the ports 102 and 104 are all connected, the selector 110 having a mixer function sets two supply paths of the charging path such that a charging current supplied from another port can be used when the charging current is insufficient. A charging controller 120 controls the battery's charging of the charging current applied through the supply path selected by the selector 110 and the charging current applied by the mixer function. A controller 140 controls a series of operations of receives a charging information about the charging state of the internal batter 130 from the charging controller 120, and displaying the charging information on a display device 150.
The display device 150 can display the charging information of the internal battery 130, such as “under charging” and “charging completed”. Also, the charging information can be displayed in various methods. For example, the charging state can be displayed in percentage (%) or bar graph.
The charging operation of the charging control apparatus will be described below. The internal battery 130 built in the body of the MP3 player is charged using one of the USB port 102 and the external input port 104.
First, when the USB port 102 is connected to the communication port of the computer, the charging controller 120 activates the corresponding charging path such that the charging current is supplied through the USB port 102 by the selecting function of the selector 110. That is, when the USB port 102 is connected to the communication port, the generation of a relatively high voltage than that of the external input port 104 is detected according to the voltage detection of a voltage detector (e.g., a diode (not shown)) provided inside the selector 110. In this manner, the charging path through the USB port 102 is automatically selected.
The charging current of a predetermined level from the computer is applied through the USB port 102. Then, the applied charging current is transferred to the internal battery 130 by the charging controller 120, thereby completing the charging operation.
During the charging operation, the controller 140 receives the charging state information of the internal battery 130 from the charging controller and displays it on the display device 150. For example, the charging information is displayed like the text “under charging” or “charging completed” or graph.
Second, when the external input port 104 instead of the USB port 102 is connected to the AC/DC adaptor 101, the charging controller 120 activates the corresponding charging path such that the charging current is supplied through the external input port 104 by the selecting function of the selector 110. Then, the AC/DC adaptor 101 converts AC power applied through a connection plug into voltage necessary for the MP3 player, and the charging controller 120 transfers it to the internal battery 130, thereby completing the charging operation. Also, in this case, the controller 140 enables the charging information of the internal battery 130 to be displayed on the display 150.
In other words, when the USB port 102 or the external input port 104 is connected to the computer communication port or the AC/DC adaptor 101, the charging path with high voltage is selected by the voltage detecting function of the selector 110. The internal battery 130 built in the MP3 player can be charged by the charging current supplied through the selected charging path.
However, the conventional charging control apparatus of the portable audio player charges a constant charging current rate even though the power is supplied from the adaptor or through the USB port. Also, the charging is performed with the identical charging current regardless of the battery voltage. Consequently, there is a problem in that a total charging time becomes longer.